In related art, crystal devices are widely used for resonators or the like. Patent Document 1 discloses an example of such a crystal device.
In Patent Document 1, an electrode land is provided on the principal surface of the first package member. A crystal oscillator is bonded to this electrode land and supported in a cantilever fashion. In a frame-shaped adhesion area provided on the principal surface of the first package member, a second package member is bonded to the first package member by means of a frame-shaped adhesive layer. The internal space of the crystal device is sealed as a result.
The crystal device disclosed in Patent Document 1 has a frame-shaped glass layer provided on the principal surface of the first package member to prevent adhesive from spreading out. More specifically, the plate-like glass layer is provided on the principal surface of the first package member, between the peripheral edge of the frame-shaped adhesion area and the peripheral edge of the principal surface of the first package member.
Patent Document 1: WO2012/140936